Windows 8 final ready for download, and there’s a 90-day trial

When Windows 7 and Vista were released, Microsoft made it easy to try out those operating systems with a 30-day trial period. In fact, you could install them without entering a product key, and some folks figured out that – with a little hackery – you could extend the trial period to 120 days.

But Windows 8 changes that. On Wednesday, Microsoft posted the final build of the new version of its operating system to its MSDN and TechNet sites so subscribers can download it well ahead of the formal Oct. 26 launch. Those versions now require that you enter a product key as part of the install process, says Windows guru Ed Bott.

If you’ve become accustomed to installing Windows 7 without entering a product key so that you can use it in evaluation mode for 30 days, you’ll definitely miss that option. After installation, activation is automatic. If you use a product key that’s already been used on another PC, you’ll be unable to personalize some parts of the Windows 8 environment.

On an unactivated PC, you’ll get regular notifications that you need to enter a valid product key. This message appeared in the upper left corner of the screen just now when I tried to visit PC Settings on an unactivated Windows 8 test PC. It didn’t appear to block any functionality, nor did the notifications degrade any features. It appears to be strictly a speed bump. (I’ll be looking into the exact implementation of activation and product key checking in the next few weeks.)

But Microsoft isn’t insisting that you buy to try. Instead of making every copy of Windows 8 trialware, the company has released a 90-day trial version of the Enterprise edition, which contains all the features of the consumer and professional editions. While Microsoft says it is aimed at developers and IT professionals, you can download it, too, so long as you have a Microsoft ID.

There are some things to keep in mind:

• You won’t need a product key to install this, but it does expire in 90 days. After that, you’ll need to do a clean install of the non-trial Windows 8 package, with a key, if you want to stick with the newer OS. You can’t upgrade the trial version. In addition, if you want to revert back to an earlier version of Windows, you’ll also have to do a clean install.

• Microsoft recommends running this on a secondary machine, on a secondary partition on your existing machine, or in a virtual environment – i.e.,by using VMWare, Parallels or VirtualBox.

• You’ve got 10 days from the time you install the trial to activate it, and if you don’t activate it or the trial expires, “the desktop background will turn black, you will see a persistent desktop notification indicating that the system is not genuine, and the PC will shut down every hour losing unsaved work.” You have been warned.

• As you’d expect, Windows 8 is a good-sized download. The 64-bit version, for example, is 3.3 gigabytes. (Yes, there’s also a 32-bit version.) If you’re data-cap constrained, keep that in mind. They’re ISO disk-image files, so you’ll need software that can burn them to a DVD or create a bootable flash or memory-card drive.

• The Windows 8 minimum specs are the same as the Win7 specs:

Processor: 1 gigahertz (GHz) or faster

RAM: 1 gigabyte (GB) (32-bit) or 2 GB (64-bit)

Hard disk space: 20 GB

Graphics card: Microsoft DirectX 9 graphics device with WDDM driver

I’ll be installing Windows 8 RTM on my home-built PC this weekend, and will have some impressions for you next week. Meanwhile, if you’ve gotten your hands on the final or trial versions, leave your thoughts in the comments.